In current storage networks, and particularly storage networks including geographically remote access nodes and storage resources, preserving or reducing bandwidth between resources and access nodes is highly desirable as well as providing optimized data availability and access. Data access may be localized, in part to improve access speed to pages requested by host devices. Caching data at access nodes provides localization, however, it is desirable that the cached data be kept coherent with respect to modifications at other access nodes that may be caching the same data. An example of a system for providing distributed cache coherence is described in U.S. Patent App. Pub. No. 2006/0031450 to Unrau et al., entitled “Systems and Methods for Providing Distributed Cache Coherency,” which is incorporated herein by reference. Other systems and techniques for managing and sharing storage array functions among multiple storage groups in a storage network are described, for example, in U.S. Pat. No. 7,266,706 to Brown et al. entitled “Methods and Systems for Implementing Shared Disk Array Management Functions,” which is incorporated herein by reference.
Fully automated storage tiering (FAST) is a technology that provides for the automated storage and movement of data according to characteristics of the data, such as frequency of use, time of last use of the data, and/or user information associated with the data, among other characteristics. Data may be automatically moved between different storage areas or tiers periodically and/or after a trigger event according to various policies based on the data characteristics, for example. A FAST system may operate in connection with thin or virtual provisional technologies in which a storage system presents a large amount of storage capacity to a host, but consumes space only as needed from a shared pool. With thin provisioning, the host visible capacity (e.g., storage perceived by the applications) may be larger than the actual allocated space on the storage system. For discussions of various automated storage tiering systems, including the use of thin provisioning, see, for example, U.S. Patent App. Pub. No. 2009-0070541 to Yochai, entitled “Automated information life-cycle management with thin provisioning” and U.S. Pat. No. 7,822,939 to Veprinsky, et al., entitled “Data de-duplication using thin provisioning,” which are both incorporated herein by reference.
Additionally, cloud computing technologies may provide for the use of online compute and storage services to execute applications in a virtual environment and in which resources may be efficiently allocated to provide on-demand compute and storage capacity over a network infrastructure. For discussions of systems and techniques for online services to provide on-demand data storage functions, see, for example, U.S. Pat. No. 7,836,018, entitled “Simultaneously accessing file objects through web services and file services;” US Patent App. Pub. No. 2009-0112811, entitled “Exposing Storage Resources with Differing Capabilities;” US Patent App. Pub. No. 2009-0112921, entitled “Managing Files Using Layout Storage Objects;” US Patent App. Pub. No. 2009-0112880, entitled “Managing File Objections in a Data Storage System;” and US Patent App. Pub. No. 2009-0112789, entitled “Policy Based File Management,” all to Oliveira, et al. and which are all hereby incorporated by reference.
It is noted that various issues may occur in connection with the management of resources using technologies like that discussed above. In particular, for example, policies, such as service level agreements (SLAs) between clients and service providers, may cause issues involving, for example, access times, processing costs and load balancing requirements among multiple data centers that are geographically dispersed and subject to varying levels of access demands depending on particular locations and/or particular times.
Accordingly, it would be desirable to provide an system that efficiently and effectively manages distributed storage to address issues like that noted above, particularly for a system in which resources are geographically dispersed.